Replacement switch needed for vintage Alps 4TR-2680

I have a 1990 Adcom AM/FM tuner that has an output slide switch on the back panel. The plastic bit has broken off and I need a replacement switch. The service manual shows it as SLIDE SWITCH 4TR-2680, and ALPS JAPAN is stamped on the metal casing. I know it is a 3 position switch but that’s about all. Alps has no reference to this part number.

Any modern suggestions that would work?

I was unable to find any information on this switch. Given the age of the device this isn’t uncommon. We know it is 3 position slide switch, so that is a place to start. For a place to start all of our 3 position slide switches are here. This is narrowed down further to what we currently have in stock.

If you could provide more information we can likely narrow it down further. Pictures would be great. As well as mechanical dimensions, mounting type, etc. The filters on the pages I linked will give you ideas of the things we need or you can use them to narrow down the search that way as well. Please let us know how else we can assist you with this.

I will take photos and measurements. The switch is “horizontal” movement relative to the mounting plane on the PCB. It is through hole soldered, and has 4 locating protrusions on the metal shell corners. The output is low, medium, and high signal. No off position.

Photos and measurements coming soon.

thank you for the support.

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The switch case is 22mm long, and stands 10mm from the PCB surface.

The switch has 10 leads, 3 positions.


It’s a right angle, through hole, PCB mount slide switch.
Here’s the search from @shawn_adams modified for that additional info:

Due to the nature of their construction, the most common 10 terminal slide switches are DP4T.
DP4T_Slide (Half Size)

However yours is 3 position, I can not come up with any xPxT switching arrangement that would use 10 pins for 3 positions.
You may need to remove it from the PCB and figure out the switching pattern with an ohmmeter.

Given the age and application It’s very possible that this switch was custom made for Adcom.

Is there any other writing on the switch body?

*ETA I only remember this much about the topic because I literally was reverse engineering an old product for work this month that includes two DP4T slide switches.


I can only see ALPS JAPAN on the top of the case. The visible side has no markings. I’d have to remove it from the board to check the case side. I’ll have to pull it and ohm it out per your recommendation.

I did find this one on Alibaba, but I see now it is an 8 pin switchj:

Here’s a snip from the PCA drawing showing that 2 of the 10 legs are not used:

Here’s a snip from the schematic confirming that it is 3 position only:

Even with this additional info I think I’ll need to pull the switch and ohm it out.

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Hello mikehd ,

Agreeing with PaulHutch this looks like a custom switch from Adcom unfortunately, or at least a very special switch we don’t carry as I wasn’t able to locate a switch similar anywhere in our system. If you are unable to locate a replacement switch you may consider routing wires to an external switch that can perform the same duties.

This may not help much, but it looks to me like schematically, it has the same pin arrangement and internal switching function as the OS203011MV9QS1. It has equal spacing between each pin and it has a “shorting” switching action, which I think is what you want in that design (it makes contact between two adjacent pins as you slide it, rather than disconnecting all pins between positions).

Unfortunately, it is a vertical slide type rather than horizontal, and I don’t know if your pin spacing even matches, but this might give you an idea of the structure to look for, or, if you’re desperate, maybe you could make a hack to access the slide selector even though it has a vertical rather than horizontal orientation.



Thanks everyone for the help. I think at this time, I’m going to live with the switch as is. It can still be actuated with a small screwdriver so at least I have a functional tuner. I appreciate all the effort that you all have put in on this request. I may contact Alps just to see if they have any NOS parts in a drawer. :slightly_smiling_face:

Take care and thanks again,